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$74+ Cheap flights from St. Louis to Baltimore (STL - BWI)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 5/19. Fares are subject to change and may not be available on all flights or dates of travel.
STL — BWI
Apr 21 — Apr 281
Tue 4/21
Tue 4/28
1 adult, Economy
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1. Tell us where you want to go

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Cheapflights Tip: The best prices from Lambert-St Louis to Baltimore/Washington are usually found in September or April, booked 75 days in advance, depart on a Tuesday or Wednesday and return on a Wednesday

Cheap flight deals from St. Louis to Baltimore

Cheapest flights from St. Louis to Baltimore
Explore the most affordable flight options available from St. Louis to Baltimore. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 22, 2026.

This Frontier deal was found by Cheapflights users on 3/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:23 pm
STL
-
BWI
1 stop10h 39m
Frontier
Sat 4/185:45 pm
BWI
-
STL
1 stop6h 34m
Frontier
Deal found 3/20$140
This Frontier deal was found by Cheapflights users on 3/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:23 pm
STL
-
BWI
1 stop10h 39m
Frontier
Tue 4/215:35 pm
BWI
-
STL
1 stop6h 44m
Frontier
Deal found 3/20$160
This Kiwi.com deal was found by Cheapflights users on 3/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/48:23 pm
STL
-
BWI
1 stop10h 20m
Frontier
Wed 5/69:25 pm
BWI
-
STL
1 stop20h 29m
Frontier
Deal found 3/18$169
This Kiwi.com deal was found by Cheapflights users on 3/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:23 pm
STL
-
BWI
1 stop10h 39m
Frontier
Wed 4/225:49 pm
BWI
-
STL
1 stop17h 41m
Frontier
Deal found 3/17$174
This Frontier deal was found by Cheapflights users on 3/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/96:29 pm
STL
-
BWI
1 stop5h 15m
Frontier
Sat 4/115:42 pm
BWI
-
STL
1 stop6h 43m
Frontier
Deal found 3/20$181
This Kiwi.com deal was found by Cheapflights users on 3/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/1611:25 am
STL
-
BWI
1 stop12h 19m
Frontier
Tue 4/2112:17 pm
BWI
-
STL
1 stop19h 33m
Frontier
Deal found 3/18$196
This Kiwi.com deal was found by Cheapflights users on 3/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/178:23 pm
STL
-
BWI
1 stop13h 58m
Frontier
Tue 4/2112:17 pm
BWI
-
STL
1 stop19h 33m
Frontier
Deal found 3/18$202
This Kiwi.com deal was found by Cheapflights users on 3/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/248:23 pm
STL
-
BWI
1 stop13h 58m
Frontier
Sun 4/268:57 am
BWI
-
STL
1 stop22h 53m
Frontier
Deal found 3/21$203
This Frontier deal was found by Cheapflights users on 3/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/26:29 pm
STL
-
BWI
1 stop5h 15m
Frontier
Tue 4/72:27 pm
BWI
-
STL
1 stop9h 58m
Frontier
Deal found 3/20$205
This Kiwi.com deal was found by Cheapflights users on 3/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/228:23 pm
STL
-
BWI
1 stop10h 39m
Frontier
Wed 4/295:49 pm
BWI
-
STL
2 stops30h 30m
Frontier
Deal found 3/21$209

Find flight deals from St. Louis to Baltimore

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Baltimore (BWI). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated March 22, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$140
(Frontier)

One-way from

$74
(Kiwi.com)

Popular in

February

Cheapest in

September

Average price

$422
Provider with most accurate pricing for Lambert-St Louis-Baltimore/Washington flight deals.
Search Deals
Provider most trusted by Cheapflights users for Lambert-St Louis-Baltimore/Washington flights.
Search Deals
From Lambert-St Louis to Baltimore/Washington
Search Deals
One-way flight from Lambert-St Louis to Baltimore/Washington
Search Deals
Highest demand for flights based on searches. 17% potential increase in price ($77 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($12 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to Baltimore that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated March 22, 2026.
Use the filters below to find and compare flights from St. Louis to Baltimore that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Wed 4/15

6:45 pm-9:45 pm

Nonstop2h 00m

Baltimore/Washington

Sat 4/18

11:50 am-6:10 pm

1 stop7h 20m

$348

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Sat 4/18

2:25 pm-7:15 pm

1 stop3h 50m

Baltimore/Washington

Tue 4/21

1:55 pm-3:15 pm

Nonstop2h 20m

$348
Quickest round-trip

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Thu 4/9

5:40 am-10:20 am

1 stop3h 40m

Baltimore/Washington

Tue 4/14

6:10 am-7:30 am

Nonstop2h 20m

$348

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Mon 4/27

4:41 pm-12:38 am

1 stop6h 57m

Baltimore/Washington

Thu 4/30

7:00 am-10:34 am

1 stop4h 34m

$351

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Sat 5/30

9:23 am-5:01 pm

1 stop6h 38m

Baltimore/Washington

Mon 6/1

8:15 am-12:11 pm

1 stop4h 56m

$351

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Fri 3/27

4:05 pm-9:10 pm

1 stop4h 05m

Baltimore/Washington

Mon 3/30

8:55 pm-12:05 am

1 stop4h 10m

$351

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Sat 4/18

7:05 am-2:00 pm

2 stops5h 55m

Baltimore/Washington

Sat 4/25

2:20 pm-8:20 pm

2 stops7h 00m

$361

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Sat 5/30

10:35 am-5:05 pm

1 stop5h 30m

Baltimore/Washington

Mon 6/1

10:00 pm-11:25 pm

Nonstop2h 25m

$364

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Tue 6/16

3:15 pm-8:30 pm

1 stop4h 15m

Baltimore/Washington

Tue 6/23

5:55 pm-7:15 pm

Nonstop2h 20m

$370

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Sat 6/6

3:45 pm-9:05 pm

1 stop4h 20m

Baltimore/Washington

Sat 6/20

4:30 pm-9:45 pm

2 stops6h 15m

$387

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/21

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

Compare providers for flights from St. Louis to Baltimore

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from St. Louis to Baltimore in March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
PricelinePrice Accuracy1 starTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*1 star

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on St. Louis-Baltimore flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Baltimore flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Baltimore flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on St. Louis-Baltimore flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Baltimore flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from St. Louis to Baltimore

Have a flexible travel schedule? Discover the best time to fly to Baltimore from St. Louis with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from St. Louis to Baltimore

How far ahead should I book a flight from St. Louis to Baltimore?

Use this chart to determine the optimal time to book a round-trip flight from St. Louis to Baltimore. Price data was last updated on March 13, 2026.

Booking 75 days in advance of your planned departure date is, on average, the best time to get cheap flights from St. Louis to Baltimore. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

What is the cheapest month to book a flight from St. Louis to Baltimore?

Currently, December is the cheapest month in which you can book a flight from St. Louis to Baltimore (average of $98). Flying from St. Louis to Baltimore in March is currently the most expensive (average of $201). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from STL to BWI?

Find hourly flight availability from St. Louis to Baltimore. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated March 22, 2026.

It’s typically best to fly out from St. Louis to Baltimore in the evening. Doing so could potentially save you 3% on the flight price compared to flying in the morning, which is usually more expensive.

What is the cheapest day to fly from St. Louis to Baltimore?

Use this chart to determine the cheapest time to fly round-trip from St. Louis to Baltimore. Price data was last updated on March 14, 2026.

Travelers seeking maximum savings on their St. Louis to Baltimore flight should consider departing on Tuesday afternoons when fares are most often at their lowest. Monday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

The best insider tips for St. Louis to Baltimore flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your St. Louis to Baltimore trip
Our travel experts
Emily Zemler

Emily Zemler

Expert on BWI

Emily is a freelance writer and book author based in London covering entertainment and travel. Her work has appeared in Los Angeles Times, Observer, and Conde Nast Traveler She has ventured to more than 40 countries and all seven continents, always in search of a great art museum. She has written extensively about hotels, luxury travel, and aviation.

Read more
Taryn White

Taryn White

Expert on STL

Taryn White is a freelance travel writer, digital creator, and travel advisor who has visited nearly 100 countries and all 50 states. She’s familiar with many airports and enjoys beach hopping, boutique hotels, spa experiences, and exploring local culture. Her work has appeared in Travel + Leisure, Condé Nast Traveler, National Geographic, Smithsonian Magazine, AFAR, and more.

Read more

Reviews of airlines servicing Baltimore

Get insights into the airlines that provide service to Baltimore. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Baltimore. Reviews last updated March 22, 2026.
Peruse reviews from past customers who have flown with Southwest,Delta, andAmerican Airlines from St. Louis to Baltimore to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,324 reviews

Overall

8.0

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Food

7.0

Crew

8.6

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Southwest
8.0
Very good
4,324 reviews
Southwest
8.0
Very good
4,324 reviews

Overall

8.0

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Food

7.0

Crew

8.6

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Delta
7.9
Good
8,314 reviews
Southwest
8.0
Very good
4,324 reviews

Overall

8.0

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Food

7.0

Crew

8.6

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
American Airlines
7.1
Good
11,487 reviews
Southwest
8.0
Very good
4,324 reviews

Overall

8.0

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Food

7.0

Crew

8.6

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Frontier
5.7
Fair
3,019 reviews
Southwest
8.0
Very good
4,324 reviews

Overall

8.0

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Food

7.0

Crew

8.6

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Baltimore. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airports do I use to fly from St. Louis to Baltimore?

    Baltimore/Washington is the airport most travelers will use when flying to Baltimore from Lambert-St Louis. Booking flights from Lambert-St Louis (STL) to Baltimore/Washington (BWI) should be relatively easy as there are 3 daily flights to Baltimore from 4 different airlines. 1h 55m is how long a flight from St. Louis to Baltimore/Washington will take if you book a nonstop flight.

  • How popular is this St. Louis to Baltimore flight route?

    Within the past month, 31 users have taken a look at flights from Lambert-St Louis to Baltimore/Washington.

  • How long is the flight from St. Louis to Baltimore?

    There are many flights that can get you from St. Louis to Baltimore in 2h. Fly via Southwest, Delta, or United Airlines to get the fastest option. The distance between St. Louis and Baltimore is about 736 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines flying from St. Louis to Baltimore round-trip?

    Frontier, at $147, was found to be the cheapest airline from St. Louis to Baltimore.Alternate airlines to your destination round-trip include American Airlines and Delta. Frontier is 59% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the cheapest airlines to fly from St. Louis to Baltimore one-way?

    For one-way options, check prices for Frontier. According to our data, you can fly for as low as $81. Users have also found prices from $106 and $110 on American Airlines and Delta, respectively.

  • What are the cheapest flights from St. Louis to Baltimore?

    The cheapest flight price from St. Louis to Baltimore is $143. On average you can expect to pay $361. The most popular route, (Lambert-St Louis - Baltimore/Washington), can usually be booked for $228.

  • Can I find deals for flights from St. Louis to Baltimore that include hotel bookings?

    Yes. In addition to deals on St. Louis to Baltimore flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from St. Louis to Baltimore?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Baltimore.

  • Can I find deals for business class flights from St. Louis to Baltimore?

    Yes. Cheapflights offers flight deals from St. Louis to Baltimore by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from St. Louis to Baltimore?

    Currently, December is the cheapest month in which you can book a flight from St. Louis to Baltimore (average of $98). Flying from St. Louis to Baltimore in March is currently the most expensive (average of $201). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Top 4 airlines flying from St. Louis to Baltimore

Discover the top 4 airlines that operate flights from St. Louis to Baltimore. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated March 22, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$147Average$218FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$196Average$377FlexibilityNo cancel feeOn-time71%
DeltaCheapest$196Average$297FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$217Average$387FlexibilityNo cancel feeOn-time63%

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